Lentus you are WRONG! I am telling you what happen Saturday afternoon. My truck was on dive on ramps. I changed the pass side shock first there was a noticeable difference in height from the driver’s side. I don't care what you say. It just happened. There are no coil springs on the front of a NBS truck there are torsion bars. No one is saying that a shock is the only thing that holds a vehicle up, it is just an additional component. I am sure when the shocks settle in the normal ride level will return, but at swap I guarantee you it raised my truck, PERIOD!
Shocks and springs work as a team to absorb the shock of the suspension. This is why there are gaps between the coil springs to allow the spring to absorb the energy of a shock to the suspension system. The shock stabilizes the vehicle during this energy absorption keeping the vehicle from bouncing continuously.
That Q&A paragraph was from a suspension specific website that I trust. It is kind of hard to disagree with the professionals. The reason why you may think that your Tahoe has been lifted is because you were used to the tired, weak shocks that were previously on there and it was causing the truck to have a bad front rake. With the new shocks, you now have tight, stiff and proper valving in the shocks that makes it seem like the truck has been lifted. So, really your Tahoe is set back to stock height, not lifted and instead of the piston in the shock being towards the bottom end of the shock body, it is now in its correct position which is somewhere in the middle or higher. Also, I've serviced so many GM trucks and SUVs that I know that the Pre-07 platforms had torsion bars...
The only shocks that are designed and engineered to hold up a vehicle are some of the leading shock companies for the offroad community. One brand in particular is Fox Racing that manufactures the Air Shox.
Ok, springs and coils do absorb the shock from the roads, however, the springs and coils DO NOT absorb it all. That is what the shocks are for. They are to smooth out the shock created by the springs/coils and to slow down the movement so that you do not loose control of the vehicle and is comfortable.
The torsion bars are, like stated before, a lateral spring and as you go over bumps, the torsion bar twists and creates the spring characteristics. Lets say you were cranking your torsion bar keys, as you crank up the bolt, you are artificially creating the twist in the torsion bar which then applies leverage to the hexagonal shape in the lower control arm that then makes the truck lift upwards.
Your shock has nothing to do with this. When you replace your shock, lifted/lowered/or stock, you are only controlling the ride.... not the ride height.
http://www.mobil1.com/USA-English/MotorOil/Car_Care/DIY/Replacing_Shock_Absorbers.htm
